Genetically modified microorganisms that have the ability to convert carbon substrates into chemical products such as isobutanol are disclosed. For example, genetically modified methanotrophs that are capable of generating isobutanol at high titers from a methane source are disclosed. Methods of making these genetically modified microorganisms and methods of using them are also disclosed.

The present invention relates to recombinant microorganisms comprising at least one nucleic acid molecule encoding a ketol-acid reductoisomerase (KARI) or modified NADH-dependent variant thereof, wherein said KARI is at least about 60% identical to SEQ ID NO: 2. In various aspects of the invention, the recombinant microorganisms may comprise an isobutanol producing metabolic pathway and can be used in methods of making isobutanol.

The present application relates to a novel promoter and a method for producing a desired substance using the same.

Related are a recombinant microorganism for producing L-valine, a construction method and an application thereof. Through transferring an amino acid dehydrogenase gene and/or activating activity of a transhydrogenase and/or a NAD kinase, reducing power of NADPH in cell is increased, the titer and yield of L-valine generated by Escherichia coli are improved, and the production of L-valine by one-step anaerobic fermentation is achieved.

Related are a recombinant microorganism for producing L-valine, a construction method and an application thereof. Through enhancing amino acid dehydrogenase activity of L-valine fermentation strain, and/or activating an Entner-Doudoroff (ED) metabolic pathway, a problem in L-valine fermentation process that reducing power is unbalanced is solved, thereby the titer and yield of L-valine produced by Escherichia coli are improved, and L-valine was produced by one-step anaerobic fermentation.

The biological production of beta-hydroxyisovalerate (βHIV) using a non-natural microorganism. The non-natural microorganism for the biologically-derived βHIV provides more beta-hydroxyisovalerate synthase activity than the wild-type parent. The non-natural microorganism can host a non-natural enzyme, such as the non-natural enzyme expressed in a yeast or bacteria, wherein the non-natural microorganism comprises an active βHIV metabolic pathway for the production of βHIV. The biological derivation of βHIV eliminates toxic by-products and impurities that result from the chemical production of βHIV, such that βHIV produced by a non-natural microorganism prior to any isolation or purification process has not been in substantial contact with any halogen-containing component.

Methods and materials related to producing isobutyric acid are disclosed. Specifically, isolated nucleic acids, polypeptides, host cells, methods and materials for producing isobutyric by direct microbial fermentation from a carbon source are disclosed.

The present invention relates to a process of producing isobutanol, including: mixing water, lactate, an enzyme mixture including at least one enzyme, at least one cofactor, and at least one coenzyme, to prepare a reaction mixture; allowing catalytic conversions of lactate in the reaction mixture for a sufficient amount of time to produce isobutanol; and separating the isobutanol from a reactant obtained by the catalytic conversions, in which the conversion of lactate into isobutanol is in association with a NADH.sup.+/NADH and/or NADP.sup.+/NADPH regenerating system.

Polypeptide scaffolds comprising enzymatic proteins are provided. The enzymatic polypeptide scaffolds comprise heterologous enzymes to form a heterologous metabolic pathway, and can be targeted to a substrate through a surface anchoring domain. The enzymatic polypeptide scaffolds leverage the high specificity and affinity protein/protein interaction between the cohesins and dockerins of microorganismal cellulosomes to form custom enzymatic arrays.

The present disclosure provides recombinant bacterial cells that have been engineered with genetic circuitry which allow the recombinant bacterial cells to sense a patient's internal environment and respond by turning an engineered metabolic pathway on or off. When turned on, the recombinant bacterial cells complete all of the steps in a metabolic pathway to achieve a therapeutic effect in a host subject. These recombinant bacterial cells are designed to drive therapeutic effects throughout the body of a host from a point of origin of the microbiome. Specifically, the present disclosure provides recombinant bacterial cells comprising a heterologous gene encoding a branched chain amino acid catabolism enzyme. The disclosure further provides pharmaceutical compositions comprising the recombinant bacteria, and methods for treating disorders involving the catabolism of branched chain amino acids using the pharmaceutical compositions disclosed herein.